It is located near the eastern contact of the Coast Plutonic Complex and the Whitehorse Trough.

Remnants of this huge caldera complex are preserved near Bennett Lake in the Coast Mountains.

The Bennett Lake Volcanic Complex was formed when the ancient Kula Plate was subducting under North America during the early Eocene period.

[1] Cataclysmic eruptions from the Bennett Lake Volcanic Complex were from vents along arcuate fracture systems that ejected out about 850 km3 (200 cu mi) of glowing avalanches of pyroclastic rock called pyroclastic flows.

Dike swarms are emplaced along ring fractures and fault zones at the southwest edge of the caldera.